Increasing interest, including concern for the environment, has lead to more and more quality control of air and water.
Analytical methods used by laboratories to analyze aqueous samples for organic components, require laboratory personnel to follow very specific and time consuming operations. As more samples need to be analyzed, laboratories are looking for new ways to handle the increased sample load, and at the same time, to provide accurate and reproducible data.
To aid in this endeavor, recent methodology improvements by the US EPA have introduced a filtration procedure, whereby organics are chemically removed from the water sample. The water sample is passed through a filter media which contains a chemical adsorbent. Once the water sample has passed through the filter, the filter is extracted with an organic solvent. This solvent is collected and later analyzed.
A number of problems are associated with this filtration procedure. First, in order to ensure the filter media is properly conditioned, the filter must be washed and soaked with organic solvents, in a proper sequence, in order to change the polarity of the filter media. As the filter media is being conditioned, it is critical that the surface of the filter media not be exposed to air. Once the water sample has been filtered, the filter media must be carefully soaked and eluted to ensure adequate recovery of the organics of interest. These time critical, and time consuming steps, make consistent and reproducible recoveries difficult to achieve.
There exists a great need for precise automated devices and methods for sample analysis.